1. Field of the Invention
The present invention relates to heat dissipation devices for removing heat from electronic components, and more particularly to a heat dissipation device combined by a base and a plurality of fins attached to the base.
2. Description of Prior Art
Conventional heat dissipation devices used for removing heat from electronic components are mostly formed by extrusion of metallic material. The heat dissipation device comprises a base, and a plurality of fins integrally extending from the base. The fins are relatively thick in comparison with distances defined between each two adjacent fins, due to inherent limitations in extrusion technology This restricts the number of the fins that can be formed, and a total heat dissipation area that can be provided by the fins. Furthermore, a height of the fins is limited to about 13 times the distance between each two adjacent fins, also due to inherent limitations in extrusion technology.
With the continuing boom in electronics technology, numerous modem electronic components such as central processing units (CPUs) of computers can operate at very high speeds and thus generate large amounts of heat. The heat must be efficiently removed from the CPU; otherwise, abnormal operation or damage may result. Conventional extruded heat dissipation devices are increasingly no longer able to adequately remove heat from these contemporary electronic components.
In order to keep pace with these developments in electronics technology, assembled heat dissipation devices have been gaining in popularity. For example, Taiwan Patent No. 319406 provides an assembled heat dissipation device 40 (shown in FIG. 3) having a base 48 for contacting the CPU and a plurality of individual cylindrical fins 42 uniformly arranged on the base 48. Each fin 42 is formed by extrusion and comprises an axile hole 42a therein. An end 42b of the fin is engaged within a slot 46 defined in the base 48.
This kind of heat dissipation device 40 has a larger heat dissipating area due to the holes 42a in the fins 42. However, the heat dissipation device 40 has at least two disadvantages as follows. First, the fins 42 are relatively thin so that a mold for manufacturing the fins 42 is difficult to be made. Second, the fins 42 are lodged within the slots 46 of the base 48 which is in contact with the CPU. It is very known that each hole 42a is sealed at an end in the base 48. Thus, dissipation of the heat in the holes 42a merely relies on conduction and radiation, especially on conduction. This design has less help to prompt heat dissipating capability. The heat removal efficiency of the heat dissipation device is still low relative to the requirement of the contemporary electronic components.